To charge expense in sales invoice and apply separate tax on it, you need to create the item master in place of expense and charge it at item level.
To generate item master for expense, you can follow the below steps:
Step 1: Go to administration section then click on master menu and click on item tab.
Step 2: Now, select add tab then specify the item name, group, n.a in unit field, tax category, HSN code and select specify here in specify sales account field and tag then expense account in it.
Step 3: After mention all the details in item master, you can save it.
To generate sales invoice and charge expense at item level, you can follow the below steps:
Step 1: Go to administration section then click on sales invoice and select add tab.
Step 2: Now, update the invoice number, date, party name, item details along with quantity and price then apply charges at item level and save the invoice.